private static void TestRange(RegexContext context, SequenceBuffer <char> buffer)
{
var backtrackState = new BacktrackState(true, context.CurrentState);
int j = 0;
while (true)
{
if (buffer.IsPastEnd(context.Index))
{
backtrackState.AddZeroConsumed();
context.Push(backtrackState);
context.MoveToNextState();
break;
}
var(matches, consumed) = MatchStateHere(context.CurrentState, buffer, context.Index);
if (!matches || consumed == 0)
{
backtrackState.AddZeroConsumed();
context.Push(backtrackState);
context.MoveToNextState();
break;
}
backtrackState.AddConsumption(consumed);
context.AdvanceIndex(consumed);
j++;
if (j >= context.CurrentState.Maximum)
{
context.MoveToNextState();
break;
}
}
}
private static void TestZeroOrOne(RegexContext context, SequenceBuffer <char> buffer)
{
if (buffer.IsPastEnd(context.Index))
{
context.Push(new BacktrackState(false, context.CurrentState, 0));
context.MoveToNextState();
return;
}
var(matches, consumed) = MatchStateHere(context.CurrentState, buffer, context.Index);
context.Push(new BacktrackState(matches && consumed > 0, context.CurrentState, consumed));
context.AdvanceIndex(consumed);
context.MoveToNextState();
}
private static bool TestExactlyOne(RegexContext context, SequenceBuffer <char> buffer)
{
var(matches, consumed) = MatchStateHere(context.CurrentState, buffer, context.Index);
if (matches)
{
context.Push(new BacktrackState(false, context.CurrentState, consumed));
context.AdvanceIndex(consumed);
context.MoveToNextState();
return(true);
}
var couldBacktrack = context.Backtrack();
if (couldBacktrack)
{
return(true);
}
return(false);
}